But when I try to I trace the Sept. 9 meme back to its source, I find only three reporters who claim any first-hand knowledge. And one of them — Daring Fireball‘s John Gruber — now says his post was just a joke.

Judging from the buzz on Techmeme, it seems to matter less what Gruber or 9to5Mac‘s Mark Gurman say. When re/Code’s John Paczkowski reports that Apple is going to reveal something on such and such a date, the rest of the press climbs on board.